Integrated circuit materials and processing technologies enable forming multiple different kinds of MEMS sensors and actuators. MEMS fabrication may leverage off established processing technologies which are used to form semiconductor materials and structures. Importantly, this may also allow integration of micromechanical devices on the same chip that holds the electronics.
Polymer materials may be used as part of the MEMS structural materials, to obtain certain advantages. Biocompatibility of certain polymers may allow use of such structures in the biotechnology industry. Such polymers may also be formed at lower temperatures then other semiconductor devices, enabling operation over a lower temperature range.
In a polymer surface micromachined process, a specified polymer, such as Parylene, may be used as a structural layer. A sacrificial photoresist layer may hold Parylene in its desired location. Acetone may be used as a releasing agent. Although Parylene structures have been fabricated in this way, it may be difficult to form freestanding devices at a sufficiently small-scale.
The present invention teaches anti stick technology to be used in MEMS formation. The anti stick technology may prevent a polymer cantilever from sticking to the substrate. In one embodiment, the anti stick technology includes a sacrificial layer that prevents sticking. In another embodiment, either one or a number of legs extend from the polymer cantilever to the substrate and are freed after formation.